The subject matter disclosed herein relates to the art of turbomachines and, more particularly, to a helical seal for a turbomachine.
Gas turbomachines include a compressor portion linked to a turbine portion through a common compressor/turbine shaft and a combustor assembly. An inlet airflow is passed through an air intake toward the compressor portion. In the compressor portion, the inlet airflow is compressed through a number of sequential stages toward the combustor assembly. In the combustor assembly, the compressed airflow mixes with a fuel to form a combustible mixture. The combustible mixture is combusted in the combustor assembly to form hot gases. The hot gases are guided to the turbine portion through a transition piece. The hot gases expand through a number of turbine stages acting upon turbine buckets mounted on wheels to create work that is output, for example, to power a generator, a pump, or to provide power to a vehicle.
Additional gases, in the form of compressed air, flow from the compressor portion into the turbine portion for cooling. Seals are provided in the turbomachine to substantially isolate the hot gases and compressed airflow for cooling. Additional seals are positioned to prevent gases at a higher pressure leaking toward gases of a lower pressure without creating work resulting in a reduction in turbomachine efficiency. Other seals are provided about rotating components to prevent compressor airflow leakage.